The present invention relates to a novel and useful light-scattering reflector and process for manufacturing the same.
Spin chucks are employed to form products which generally possess a unitary configuration, typically with a cavity. In general, the product is formed on a chuck by rotating the chuck about an axis and moving a roller or multiplicity of rollers one or more times along a sheet of material to pressure the sheet against the chuck. In this manner, the sheet, which may be metallic, conforms to the configuration of the chuck to produce the article.
For example, U.S. Pat. Nos. 4,117,704; 4,408,472; 4,953,376; 5,220,817; and 5,775,151 describe methods and apparatuses for using a spin chuck-type method to form articles.
U.S. Pat. No. 5,465,598 describes a method for forming an annular member by rotating a convex dye.
U.S. Pat. No. 5,640,867 shows a method and apparatus for forming a rim on a lamp reflector employing a roller which is also used to form the annular body on a spin chuck.
Lamp reflectors are often curvilinear in cross-sectional configuration. That is to say, reflectors for lamps may take forms other than right circular cylinders. In most cases, the inner surface of an annular lamp reflector is specular, reflecting or diffusing light from a lamp located at or near the inner chamber of the reflector. It has been found that it is highly desirable to alter the reflecting surface, normally the inner surface, of an annular reflector to achieve light scattering, which sometimes is referred to as "glow". To accomplish this task, prior reflectors are normally formed on a spin chuck or by other methods followed by alteration of the inner surface of the reflector to create uneven surface texture. For example, the inner surface of lamp reflectors have been sandblasted or peened to produce roughness or bumps, respectively. Unfortunately, these method have produced a very bright type of reflection, which has been deemed to be undesirable. In addition, the inner surfaces of lamp reflectors formed on spin chucks have been subsequently chemically etched with an acid or base solution. However, the reflection, again, is very bright and, thus, undesirable. It has been proposed that the spin chuck itself be peened or sandblasted however prior attempts by others have resulted in lamp reflectors that become fixed to the spin chuck following formation by a roller through the spin chuck method. Such manufacturing problems are particularly vexing with curved reflectors.
Molding of reflectors from plastic-like material have met with the same problems in that textures on the mold prevent removal of the plastic reflectors from mold, rendering such processes as inoperable.
A reflector formed from a spin chuck method which possesses a reflecting inner surface capable of scattering or producing diffuse light would be a notable advance in the lighting industry.